The authors report the results of the study of 435 bacteriological samples taken in children presenting with acute otitis media, in the out-patient department of ENT at the hospital Bretonneau (Paris) and in Valognes (Manche) from October 1981 to September 1987. Three bacterial organisms prevailed: Haemophilus (37 and 22% respectively), S. pneumoniae (25 and 7%) and Staphylococcus (16 and 17%). Pseudomonas was fairly frequent in cases with otorrhea, even when recent. Comparison with other studies shows the clear progression of the incidence of Haemophilus in acute otitis media. The percentage of the strains secreting a beta-lactamase was 17% whether the children live in the country or in town. The frequency of S. pneumoniae was independent of age but was clearly lower in cases with prolonged or relapsing otitis. According to these results, the authors discuss the therapeutic strategy for acute otitis media. Amoxicillin still remains the antibiotic of choice. In case of persisting or relapsing otitis, the bacteriological examination will allow choosing the best adapted antibiotic: first generation cephalosporin, clavulanic acid and amoxicillin or trimethoprime and sulfamethoxazole.